Pisa syndrome in Parkinson’s disease: an electrophysiological and imaging study

Abstract

The pathophysiology of postural abnormalities in patients with Parkinson's disease is poorly understood. In the present study, 13 patients with Pisa syndrome (PS) underwent EMG study of paraspinal lumbar (L2-L4) and thoracic (T8-T10) muscles, and of non-paraspinal muscles. Patients also underwent a whole spine X-ray and an MRI assessment of paraspinal muscles (L1-S1). The EMG evaluation disclosed two main patterns: patients with pattern I (n = 6, hyperactivity of lumbar paraspinals ipsilateral to the trunk leaning side) or pattern II (n = 7: hyperactivity of lumbar paraspinals contralateral to the trunk leaning side. In pattern I, half the patients also had ipsilateral hyperactivity of the thoracic paraspinals, the other half had contralateral thoracic hyperactivity; in pattern II, thoracic paraspinal hyperactivity was contralateral in all patients (like the lumbar paraspinal hyperactivity). Non-paraspinal muscles were hyperactive ipsilaterally in four of six patients with pattern I and in all patients with pattern II. The MRI showed mild muscular atrophy with fatty degeneration in patients with pattern I, whereas in pattern II patients this was greater and prevalent on paraspinal lumbar muscles ipsilateral to the leaning side. The present data support the hypothesis that two main patterns of muscular activation are associated with PS. In both patterns, hyperactivity of contralateral paraspinal muscles is probably compensatory for the trunk leaning.

Mood and behavioural effects of subthalamic stimulation in Parkinson's disease

“…72 More recently, a magnetic resonance imaging study showed bilateral paraspinal lumbar muscle atrophy that was unrelated to the side affected by the deviation, and more pronounced in hypoactive muscles as shown by EMG recordings. 73 Although these data are difficult to interpret, they do not support the notion that musculoskeltal mechanisms play a primary role in Pisa syndrome. Moreover, primary myopathy would also be incompatible with the rapid onset of Pisa syndrome seen after medication changes or surgical treatment for PD.…”

“…Electromyographic (EMG) recording of paraspinal muscles failed to show any pattern of denervation or myopathy, 36,72,73 except in 2 of 26 patients in one study. 7 Very few imaging studies have been performed on the paraspinal muscles.…”

Insidious onset of Pisa syndrome after rasagiline therapy in a patient with Parkinson’s disease

“…This suggests that the drug alone is probably not sufficient to induce the syndrome, but a combination of genetic and clinical PD characteristics might be needed [4]. On this regard, it has been suggested that PS may represent a complication of advanced PD in patients showing marked asymmetry of symptoms, and detectable hyperactivity of the paravertebral muscles on the less affected side, as we observed in our patient [5].…”

Pisa syndrome in Parkinson's disease: diagnostic and management challenges

“…The aim was to 1) investigate activation pattern of the axial paraspinal muscle and 2) find signs of possible denervation or myopathy. Tinazzi et al 50 detected two different patterns of muscular activation: a hyperactivity of lumbar paraspinals ipsilateral to trunk bending side and hyperactivity of paraspinals contralateral to trunk bending side. These observations suggest that a dystonic activity could play a role in determining the bending ipsilaterally to PS and that the contralateral excessive muscle activation represents a compensatory mechanism.…”